Don't you hate being a font-rendering snob and then realizing you've been staring at something ugly for months without realizing it?

I'm not being snide; it's happened to me. I used to be a typesetter, and yet when I had trouble using Inconsolata in Sublime Text, I reverted back to Menlo, which I hated - and spent the next few months preaching about how hard I'd worked to find the Perfect Programmer Font For Me, not realizing I wasn't actually looking it in the editor. Worse, I was seeing it in Terminal; I had no excuse.

It's the visual equivalent of the classic audio production goof: You spend hours tweaking a particular equalizer setting, everybody agrees that it sounds perfect now, and then realize the EQ hasn't been patched in at all and you've been changing nothing.